Tuesday, 28 February 2012

Basic Face Shading Tutorial - updated 6th March

Something I've been meaning to do for a long time, just got round to finishing it:

Tutorial after the jump

Rendering skintone is something that’s fascinated me ever since I discovered how much I could do with it.  It is something that, superficially, can seem a relatively easy thing to render – get a light, medium and dark flesh tone and that’s it.  Once you look at it more in depth, though, it’s actually so much more complex than that.  There are factors that are crucial to simulating realistic skin but are often overlooked, like underlying facial structure, facial planes, skin tone variation and lighting, which results in skin that looks plasticky, wooden or just plain flat and dull.
This is by no means an exhaustive tutorial, because I feel that if I were to write down all the techniques and observations I gathered over the years about painting skin and facial anatomy, it would fill an entire book!  The aim of this tutorial is to go over my basic workflow and briefly go over each feature and other important elements that ‘bring’ the face together and give it ‘life’.  It shouldn't be taken as the definitive guide to face painting and I strongly encourage you to experiment and find out the workflow that you're most comfortable with.  Due to the massive variation in skin and eye colours and shapes of each feature, I shall not go into the nitty-gritty of choosing the palette for skin tones or how to draw eyes, nose and lips, because each of these are very vast subjects that deserve standalone tutorials, or perhaps even a book dedicated to them!  For the sake of simplicity, the scope of this tutorial largely excludes more esoteric aspects of the subject such as specular lighting and reflective lighting.

Lighting is often taken for granted, but it is everything.  It affects where and how the shadows will be cast and what hues the skin will pick up.  Other overlooked facts are that skin isn’t completely opaque and it can reflect light, and this will interact with ambient or a direct light source and affects the hue of the skin.  So, before you start, think about what the light source(s) is, even if not going to be apparent or as simple as frontal lighting.  Even the most diffuse lighting will have an effect on how the skin will look.
For the sake of simplicity, this tutorial will feature a figure whose face is shown in frontal view with a single frontal, distinct light source that’s angled slightly to the top left.

Over the past year since I started working as a freelance illustrator, I found that the most efficient way to shade a face is to start dividing the shading into 5 tiers:
Light-light, mid-light, mid-ground, mid-shadow and dark shadow.

It’s not too terribly interesting at the moment, I know.  Just a bunch of dark and light flesh tints, but what you want to do at this stage is to get the values down first and worry about the variation of hues later.
I start laying down the flat colour with the mid-ground colour and then work my way outwards; mid-shadow is next, then mid-light, then dark shadow and finish off with light-light.

 
It’s important to make the mid-ground colour somewhat darker than you think, even if the figure you are painting is very fair skinned; it’s a lot easier to simulate depth and add highlight when the base colour is very neutral than it is when the base colour is already light.  This is true for hair, eyes and lips colours as well – use a neutral dirty mousy colour for the hair if you’re going to make the figure very blonde, and use a grey on the white of the eyes rather than white or off-white.  Most magazines and printed ads would have you think that people invariably have this impossibly bright white sclera (the white area of eyes), but that’s because the whites of those people in the ads are heavily retouched to have an immediate impact to the viewers.  Under normal circumstances and lighting, most people’s sclera is some shade of off-white.

I started laying down the shading with the mid-shadow shade first. Laying down the base colours at this stage in large blocks is really important because it provides a general description of the relief of the face and gives it a direction of where the highlights and further shadows will go.
 
I worked on the rest of the features, like eyes, lips and hair at the same time at this stage so that everything is roughly on the same stage of completion.  For me, it’s a lot easier to visualize how the completed picture will look like if I work this way, rather than completing one section and then moving on to the next.
Pay attention to the commonly overlooked areas – lower lid, tip of nostril, between eyebrows, underside of top lip.

I also redrew the nostrils and the jawline so they don’t get lost.

Next comes the mid-highlight.
 
I painted over the ‘pencil’ lines at this point just to smooth everything over.

The dark shadow bit is rather tricky, and introducing it can initially look like it’s too much.  What I did is use a smallish semi-hard round brush to paint on the most recessed and shadowed areas of the face.  The contrast of this tint is rather stark when compared to how the shading previously looked like, so you have to work on blending it in a bit more than in the previous stages.

I used a soft brush in semi-high opacity, went over it lightly, then picked an intermediary colour and then paint over it again.

 
.  Repeat until it’s smooth.


The next stage, laying down the light-highlight, is just as tricky as the dark-shadows, because it’s so light, so I did pretty much what the same thing as what I did in the last stage; I first use a semi-soft round brush at a somewhat high opacity to paint patches of colours on areas of the face that are normally highlighted – bridge and tip of nose, on the cheeks, inner corners of the eyes, middle of forehead and chin and on the neck and collarbone.
 Then, colour-pick the intermediary colours and use a soft round brush to blend.

Keep on blending and then picking the new intermediary colours and then blend some more.  Repeat until smooth:

Remember when I told you to use a grey for the flat colour of sclera? Now you get the chance to change that.  The first thing you need to do as you start painting the eyes is to get the feel of the shape of the eyeball.  It’s roughly spherical in shape and the shading needs to reflect that, and the area surrounding it should show the shape of it as well.
An illustration showing how the shape of the eyeball influences the shading of the sclera.

Like the skin, treat the grey that you use to fill in the sclera colour as a mid-ground colour, and use an off-white shade to lighten along the edges of the iris, and use a darker  grey to shade the corner of the eyes.

Another important thing to consider is that the inner rim of the upper eyelid casts shadows on the eyeball.  This is something that’s often overlooked but it adds a lot of depth and realism to the eye.
 
After I’m done with the eyeball, I moved on to the eyelids and the area that is immediately surrounding the eyes.  At this stage I’m trying to get the feel of the underlying structure and relief of the area and how it affects the shading.
 The pink lines show how the shape of the eyeball affects the shading of the area surrounding it.

I first start with the eyelids and work my way out. I use a dark reddish brown shade to shade the entire top and bottom eyelids, except for the top middle bit of the upper eyelid, and a little bit beyond, especially on the outer upper corner of the eye.  I use a lighter flesh shade on the inner corner of the eye.
 I made the shading along the upper and lower lid crease slightly darker; this helps to emphasize the lids and the overall shape.


Then I smoothed and lightened the shading along the eyelid, especially on the lower inner to middle lid so it doesn’t look like she has so much makeup on, and to give the shading a more gradual transition from the inner corner of the eye.  I darkened the shading of the outer part of the eyes, especially on the crease area because the hair on the outer edge of her eye casts a shadow on that area as well.  I also used a darkish orange-red colour to colour in the tearduct.

I work on the area further by adding highlights along the inner corner of the eye, inner areas of upper and lower lid, in patches along the lower inner rim (it’s lighter along the middle area and darker towards the edges due to lighting) and up towards the browbone to enhance the shape and the structure of the eye.  I also added a little dark patch just below the inner corner of the eye to add a slight ‘imperfection’.  You don’t have to do this if you don’t want to, but I like it this way.  I’ve found that even with my own eyes, this area is always a bit darker, no matter how much I try to cover it with makeup. 
 At this point I wrap up the eyes area by painting in eyelashes and eyebrow.  I use a small, hard edged brush and paint them in clusters.  Keep in mind that they don’t grow in one single neat direction or always fan outwards like the ones you see in false lashes.  A little irregularity helps with the realism.  When you paint the eyebrows, there is really no need to paint every single strand of eyebrow hair; I use a medium brown, semi-soft brush to suggest the mass of the eyebrows and darker brown to paint in the strands, following the direction of eyebrow hair growth. 


Before you start shading the nose, it’s helpful to visualize the relief of the area.  I drew this mesh grid to illustrate how the relief would look like, though there’s no need to do this every time you draw a nose (I don’t.)

 
Another method that may be useful in helping you visualize the nose area is to think of it as a compilation of polygonal geometrical shapes:
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I decided that the bridge of the nose is well defined enough, but the tip of the nose needs to be refined more.  I use a dark brown colour to trace the nostril area, with a bit of an emphasis on the lower right (our left) where the tip of the nose casts a shadow.
 
At this stage it’s just lightly brushing a muted reddish brown colour over the area because I noticed that the hue of the area is slightly less saturated than the rest of the face, so this is just to add more warmth and depth to the shading of the area.  
 After I smoothed the shading and darkened the nostrils, I added a little bit bright orange just at the very tip of it, along the septum and on the shadow that the nose casts for a bit of a ‘pop’.  I also notice that, especially in fair-skinned people, the nose area tends to be a little bit rosier than the rest of the face.  
 
Another thing to keep in mind is to shade the area where the top corner of the nostril meets the face, to hint at the start of nasolabial fold.  This exists even in the youngest of subjects, and I think it’s a very important yet often overlooked area, because otherwise the nose can seem unnaturally attached to the face or it can make the face look somewhat plasticky.

I openly admit that even after all these years, lips are the one facial feature that I still have a bit of difficulty with.  I think it’s because I had such a fixed preconception of how to render lips, and constantly got frustrated when they don’t come out quite right.  The most stunning revelation that occurred to me about painting lips is not really about the actual lips themselves, but about the structure and the area surrounding the lips.  It is as important as painting the actual lips themselves; it provides a structural base on which the lips sit, and in some cases, you can get away with somewhat less work on the lips with a well-defined surrounding area.

There are little nuances on the lips that I previously never noticed that make a huge difference in how the lips look, like the vermillion border (where the skin of the lips meet the skin of the face – probably just a big fancy term for lipline), which vary a lot from person to person and often even on the same set of lips!  Usually, the vermillion border of the upper lip is a lot more distinctive than that of the lower lip, and sometimes a paler border would run along those edges.  I also found out how important it actually is to highlight and define the cupid’s bow and philtrum (the little groove between the nasal septum and the dip of the cupid’s bow.)
 
Anyway, back to the main shape of the lips.  Note that the line separating the upper and lower lip is rarely straight; they’re usually shaped like a very lightly-cuved, overly stretched-out ‘m’ that flick upwards as they reach the corners of the mouth.  Getting shadows and highlights in the right places is integral to giving the lips realistic volume and softness here. 

As with nose and eyes, I think it’s also very important to visualize how the lips would look in real space.  I drew a couple of red lines running down the length of the lips to illustrate how the relief would look like,
 
and how the peaks and valleys, along with the light source, affects the shading on the lips.

 
As I proceed to smooth the shading, I varied the saturation and the colour on the lips.  Note how the the central area of both top and upper half of the bottom lips are relatively pale and desaturated, almost like a skin colour, while the bottom and the edges of the lips are more saturated.  Painting the glint on the lips is my favourite part because I just love shiny stuff.  I used a small, hard edged brush, pick a very pale pink colour and just go over it, painting them in little dots and dashes, and occasionally alternating it with dark reddish brown colour so that it will pop out a bit more. 



Anything after this are just finishing touches, really, if you don’t count painting hair.  As I zoomed out, it became apparent that the contrast and details of the rest of the face doesn’t match those of the facial features, so I went over the facial outlines and the deepest shadow areas again with a dark brown colour.

 
Even after smoothing out the shading, the hues on the face still looks relatively dull, so I used a series of brighter pinks and oranges to add to a bit of rosiness and colour to the face.  I used three colours instead of one and build it up in very light layers because I have found out that I can achieve a more subtle and natural gradation this way:

 
The pink and orange that I used are very bright and saturated, but I find that using very bright colours but with a very light hand simulates the skin’s translucency better than a heavy-handed application of a more muted colour.
 
At this point I went over the deep shadowed area of the face with a more saturated reddish-brown colour just to bring the saturation level up.
Then I painted the hair and made some glowy blue halo light-thing around her on a whim, because my attention span is super short and making a shiny glowy thing is just a way of rewarding myself for sticking with this to the end!

That’s all and thanks for reading!

9 comments:

George Patsouras said...

cThat's brilliant, great mastery of the face and some splendid colors, you should be very proud of this piece!

kayness said...

Thank you George! It's so great to see such a validation from you.

DON CARVALEZ said...

Very cute tutorial.Isn't basic but advanced.

kayness said...

Hi Don, thank you so much for the comment. Yes I suppose it is rather advanced! I just think that if I didn't limit myself, I could just go on forever about painting skin tones and hair and eyes and whatnot. I love this subject and I think that if I were to write everything I know about it, I'd have a large book written! Of course I have followups planned, now I just gotta do them! :D

Mary Stebbins Taitt said...

Excellent tutorial, I read it all and hope to return to read it again. I am just a beginner, so stuff like this is helpful. (I never went to art school--was a biologist before I retired.)(I am sure you can tell, LOL!)

Nicely done and helpful. And kind of amazing.

Mary Stebbins Taitt said...

1)if you have other tutorials, perhaps you could tag them "tutorial" so the tag will show up on the sidebar and readers coudl click on it.

2)with your permission, if I have time, I might post on my blog about this tutorial.

kayness said...

Hello Mary
Sorry for the late reply!

1) Yes, I do have another tutorial actually. It's old and it's on my deviantart, i'm not sure if I like it anymore, but people seem to do love it:
http://kay-ness.deviantart.com/gallery/?offset=24#/dvpf6d

2) I would really appreciate it!

Sofia Vampertzi said...

Hi!

was wondering about which tools you used, you mentioned semi-hard round brush, is it the same brush you use for the whole painting or? do you use a lot of shadows/lights do create such realistic skin?

Tamara Patrick said...

Thank you so much for sharing, I'm currently trying to develop more into digital painting and this tutorial really helps. I admire you for your effort in sharing your workprocess! Love your work btw! ;)